How to make social media effective for Crowdfunding campaign in converting into pledges?

Everywhere I read social media seems very effective in driving traffic to Crowdfunding campaign. We plan to launch a Crowdfunding campaign in few days. I wonder if anyone has any suggestion to make social media drive to bring pledges to our Crowdfunding camapign. Majority seems using Facebook. Any thoughts on Twitter, Reddit, etc.

We are bootstrapping and running on very thin budget. Hence we are looking to run social media campaign with little or no costs.

Social media was hugely important for us, but we also drove traffic through
a press release, writing blog posts, articles, and we paid for some PR as a
way to make social media posts more interesting. Here's a lessons learned
piece I wrote last year:
http://www.presidioedu.org/blog/amps-crowdfunding-campaign-lessons-learned/

I am also considering a crowd funding campaign soon. The advice I read was to locate effective communicators and leaders by researching campaigns of firms similar to yours. Then go through your network to try to get personal introductions to these influencers. It isn't easy to reach the prominent influencers, but if you do, your campaign will have a much higher chance of success.